The present invention relates to a bump-bonding heating apparatus for heating a semiconductor wafer placed on the heating apparatus to a bump bonding temperature in a process of forming bumps at electrode portions on circuits formed on the semiconductor wafer, a bump bonding method to be carried out by using the bump-bonding heating apparatus, a bump forming apparatus equipped with the bump-bonding heating apparatus, and a semiconductor wafer having bumps bonded by the bump forming apparatus.
Conventionally, a bump forming apparatus is equipped with the bump-bonding heating apparatus. As shown in FIGS. 24 and 25, in the conventional bump-bonding heating apparatus 1, gas is jetted out, through gas jet paths 4 opened at a heat stage 2, to a semiconductor wafer 3 which has been carried into the bump-bonding heating apparatus and placed on the heat stage 2 so that the semiconductor wafer 3 is heated to a bump bonding temperature. By this gas jet, the semiconductor wafer 3 is rotated circumferentially of the semiconductor wafer 3 on the heat stage 2 so as to be set to a preset rotational angle. For such a gas-floating type direct turning method for the semiconductor wafer 3, only a gas supply unit 5 needs to be provided as a structure for turning the semiconductor wafer 3. This allows the bump-bonding heating apparatus 1 to be made compact, and thus this direct turning method is preferable.
However, the bump-bonding heating apparatus of the above structure has the following problems. That is, in the case where the semiconductor wafer 3 is a charge-producing semiconductor substrate that produces charges from temperature differences due to the heating to the bump bonding temperature or other reasons, the charge-producing semiconductor substrate, when mounted on the heat stage 2, is electrostatically adhered onto the heat stage 2 by the electrification of the charge-producing semiconductor substrate. Also, in order to turn the semiconductor wafer 3 to the preset rotational angle, it would be necessary to control a pressure, flow rate and the like of the gas jet according to a size and weight of the semiconductor wafer 3, making the apparatus difficult to handle. It is also difficult to turn the semiconductor wafer 3 to the preset rotational angle at high accuracy.
Meanwhile, without adopting the gas-floating type turning method for the semiconductor wafer 3, a structure in which the heat stage 2 with the semiconductor wafer 3 held thereto is rotated could be conceived. This structure, however, would involve increasing the size of the apparatus, disadvantageously.